A new set of pictures from the Red Planet joins a growing gallery of images and raises the prospect that water was present relatively recently on the surface of Mars.

The latest evidence uncovered by NASA's sharp-eyed Mars Global Surveyor orbiter shows small channels etched into sand dunes inside an impact crater in the planet's southern hemisphere. Scientists believe the channels might have been cut by flowing water.

gallery： 画廊, 图库；关于证明火星上曾经有水的图片越来越多。

sharp-eyed：目光敏锐的。

orbiter： 人造卫星；这组图片是NASA的火星卫星拍摄的。

crater： 弹坑，坑洼。

The findings, released by Global Surveyor's camera operator Malin Space Science Systems, follow publication earlier this year of photographs showing similar geographic traits that scientists believe were formed within the last million to two million years.

If the gullies and channels were indeed cut by running water, Mars may have had rivers much more recently than previously believed, says Kenneth Edgett, a co-investigator at Malin Space Science Systems. Liquid water is believed to be a key component needed for the existence of life.

finding：发现, 发现物。

geographic：地理学的, 地理的。

gully：沟渠；科学家认为照片中的沟渠是水流冲刷出来的。

component：成分；液态水是生命存在的必须条件。